When a resize is confirmed the instance does not belong to the source
compute any more. In the past the scheduler instance info is only
updated by the _sync_scheduler_instance_info periodic. This caused that
server boots with anti-affinity did not consider the source host.
But now at the end of the confirm_resize call the compute also updates
the scheduler about the move.
Change-Id: Ic50e72e289b56ac54720ad0b719ceeb32487b8c8
Closes-Bug: #1869050
(cherry picked from commit 738110db74)